Mine is generally stored up above in my garage at home (never used it) You'll know it when you find it. If I remember correctly it is much thinner than the aft cabin fillers.
If anyone gets a chance could you please post a picture of the clips that hold the grill in at the AC discharge in the v-berth. (Rectangular grill located below the starboard side locker, floor level) Mine have somehow come up missing and can't for the life of me remember what they looked like...